Identifying bark beetles and their damage.

Adults are small, dark, cylindrical insects about the size of a grain of rice; they can fly from tree to tree. Larvae are tiny grubs that feed beneath bark on branches and trunks. Infested trunks and branches have many tiny holes where beetles have bored in or emerged. Tree sap or dust from boring can exude from holes. If you peel back bark on infested trees, you’ll see galleries, or tunnels, from adult or larval mining.

Bark beetles injure trees by disrupting the flow of nutrients.

Adults and larvae feed in the area of the inner bark that transports food through the tree. Infested trees can die in one season, causing limb drop and fire hazards.